A controller of a magnetic tape library apparatus finds individual information such as an error rate, the number of mounting times, and the like for each of multiple magnetic tape cartridges accommodated in a cell. Accordingly, a magnetic tape cartridge has an attached barcode label indicating a serial number and the like, and a built-in cartridge memory recording the updated individual information. In reading the individual information from the cartridge memory, a robot which is built in the magnetic tape library causes a unit having the same shape as that of the magnetic tape cartridge and including a reader mounted to read the individual information to face the magnetic tape cartridge.
A related technology is disclosed in Japanese Laid-open Patent Publication No. 2007-188615.